CHAP 12&13

• Health Care Epidemiology


  The study of the occurrence, determinants, and distribution of health and disease within health care settings
• Infection Control & Prevention of Health Care Associated Infection


  The primary focus of health care epidemiology
• Health Care-Associated Infections (HAIs)


  Infectious diseases that were acquired within health care facilities
• Community-Acquired Infections


  Infectious diseases that were acquired outside of health care facilities
• 4 most common gram-positive bacteria that are the most common causes of HAIs in the US

  • Staphylococcus aureus
  • coagulase-negative staphylococci
  • Enterococcus spp.
  • Clostridium difficile
• 4 most common gram-negative bacteria that are the most common causes of HAIs in the US

  • Escherichia coli
  • Pseudomonas aeruginosa
  • Enterobacter spp.
  • Klebsiella spp.
• 4 sources of pathogens that causes HAIs

  • Healthcare Professionals
  • Healthcare Workers
  • Visitors
  • Patients
• Approximately 70% of HAIs bacteria are drug-resistant
• 5 most common types of HAIs

  • Clostridium difficile
  • Urinary tract infections
  • Surgical site infections
  • Lower respiratory tract infections
  • Bloodstream
• Patients Most Likely to Develop HAIs
• Handwashing The most important and most basic technique in preventing and controlling infections and preventing the transmission of pathogens.
• Handwashing


  Numerous measures taken to prevent infections from occurring in health care settings
• Asepsis

  Means "without infection"
• Medical Asepsis

  Precautionary measures necessary to prevent direct transfer of pathogens from person to person and indirect transfer of pathogens through the air or on instruments, bedding, equipment, and other inanimate objects (fomites)
• Surgical Asepsis or Sterile Technique


  Practices used to render and keep objects and areas sterile
• Medical asepsis

  Is a precautionary measure
• Surgical asepsis


  Is a sterile technique
• Goal of medical asepsis


  To exclude pathogens
• Goal of surgical asepsis


  To exclude all microbes
• Standard Precautions


  To be applied to the care of ALL patients in ALL health care settings, regardless of the suspected or confirmed presence of an infectious agent
• Transmission-Based Precautions


  Used for patients who are known or suspected to be infected or colonized with highly transmissible or epidemiologically important pathogens for which additional safety precautions beyond Standard Precautions are required to interrupt transmission within health care settings
• Types of Transmission-Based Precautions

  • Contact Precautions
  • Droplet Precautions
  • Airborne Precautions
• Direct Contact

  Transfer of microorganisms from body surface to body surface
• Indirect Contact


  Transfer of microbes through a contaminated intermediate object
• Norovirus


  Can remove from contact enteric precautions once asymptomatic for 2 days
• Clostridium Difficile Infection


  Remains in contact enteric precautions for duration of hospitalization
• Adenovirus Gastroenteritis


  Requires contact enteric precautions if diapered or incontinent
• Diseases Requiring Droplet Precautions

  • Influenza
  • Meningitis
  • Mumps
  • Pertussis
  • Rhinovirus
• Diseases Requiring Airborne Precautions

  • Tuberculosis
  • Measles
  • Varicella/Zoster
• N95 Respirator


  Used when Airborne Precautions are indicated
• Negative Pressure Airborne Infection Isolation Room (AIIR)

  Under negative pressure
• High Efficiency Particulate Air (HEPA) filter


  Used in Airborne Infection Isolation Room (AIIR)
• Positive Pressure Protective Environments

  Under positive pressure
• OSHA

  Occupational Safety and Health Administration
• Disinfectants

  • Alcohols (60-90%)
  • Chlorine Compounds
  • Glutaraldehyde
  • Iodine Compounds
  • Phenolic Compounds
  • Quaternary Ammonium Compounds
• Alcohols (60-90%)


  Used for equipment & rubber stopper disinfection, it denatures proteins
• Chlorine Compounds


  Used for floors, countertops, BSCs. It denatures proteins
• Glutaraldehyde


  Used for disinfection of medical equipment (endoscopes, etc.) It interferes with DNA, RNA, and protein synthesis
• Iodine Compounds


  Mainly used as an antiseptic, it disrupts protein and nucleic acid structure
• Phenolic Compounds


  Used for floors, countertops, BSCs. It disrupts cell walls & inactivate enzymes